Parser generated on Bison 1.5 (and later) does not start a parsing

[Baruch Gudesblat]

Hello, all.

I hope some one already faced this problem in past. Who can help, please?


My Verilog parser, generated by bison does not start a parse process. It
happend in bison 1.50, 1.875c and latest 2.4.3
But it works fine, when generated with bison 1.35 !!!
What has changed from 1.35 to 1.50?

*The problem:
*
Parser bison:

#define YYTRACE(str) fprintf(stderr, "  <Yacc>%s\n", str);
%%
source_text        :
          {  YYTRACE("sorce_text:");
             $$ = vl_description = vl_create_desc("stdin");          }
        | source_text description          {
              YYTRACE("source_text: source_text description");          }
        ;
description : module
          {  YYTRACE("description: module");          }
        | primitive
          {  YYTRACE("description: primitive");          }
        ;
...
...


Input file:
    module upi_top ;
    endmodule


When the parser runs it just print:
  <Yacc>sorce_text:

and calls to *yyerror* procedure, when error_msg == "syntax error" and
yytext == "module"


I would be very thankful if some one could advise me how to start to debug
this case*.*



-- 
   -Thanks
   -Baruch